Na+/Ca2+ exchange mechanism is one of the ion transport mechanisms that regulate the concentration of sodium and calcium ions in the cells. Compounds which selectively inhibit Na+/Ca2+ exchange mechanism and thereby prevent overload of Ca2+ in cells are regarded useful in preventing the cell injury mechanism of cardiac muscle and the like after ischemia and reperfusion. Such compounds are useful e.g. in the treatment of ischemic diseases such as heart diseases, ischemic cerebral diseases, ischemic renal diseases and in the protection of cells during thrombolytic therapy, angioplasty, bypass operation of coronary artery or organ transplantation and arrhythmias.
Compounds capable of inhibiting Na+/Ca2+ exchange system have been described earlier e.g. in patent publications WO 97/09306, EP 0978506, EP 1031556, JP 11049752 and JP 11302235.